Current Sensitive Preamplifier Research Articles

A low-noise current-sensitive preamplifier VIEC based on a charge-sensitive preamplifier

A low-noise current-sensitive preamplifier VIEC has been developed based on the circuitry of a charge-sensitive preamplifier. In this paper, the dynamic ranges of the VIEC and a conventional current-sensitive preamplifier are measured and compared. A method to increase the dynamic range of the VIEC is described. Using the VIEC with enhanced dynamic range, a computed tomography measurement is performed for a strongly attenuating phantom comprising a 10-cm-diameter acrylic cylinder with a 3-cm-diameter iron rod in the center. • Low noise current preamplifier VIEC showed wide dynamic range. • Further enlargement of the dynamic range of the VIEC is proposed and demonstrated. • Computed tomography image and profile of a strongly attenuating phantom are shown.

A Method for Calculating Characteristic Value to Characterize the Induced Charge in Electrostatic Tomography

Electrostatic tomography (EST) is a technology that uses the induced charge on the electrode surface to reconstruct the parameter distribution of gas-solid two-phase flow. The induced signal is dynamic, whereas the induced charge required in the image reconstruction theory is static. Therefore, it is necessary to calculate the characteristic value of the signal to characterize the induced charge before image reconstruction. However, the calculation methods of characteristic value are different at present, and there is a lack of unified understanding. For the above problem, this article analyzes the mechanism of signal induced by the charged single particle, compares the differences between the charge-sensitive and current-sensitive preamplifiers, and comes to the conclusion that the current-sensitive preamplifier is more suitable for the measurement of induced charge. By further studying the output signal of the conditioning circuit with the current-sensitive preamplifier, root mean square of charge (RMSCE) is proposed to characterize the induced charge. Simulation and experimental results show that RMSCE has stronger characterization ability for the induced charge and can be used in EST system to obtain high-quality reconstructed images.

A low-noise current-sensitive preamplifier for X-ray computed tomography with applying a charge-sensitive preamplifier

ABSTRACT A low-noise current-sensitive preamplifier was developed for aiming low-dose X-ray computed tomography with applying a charge-sensitive preamplifier. We compared the number of X-ray photons needed for current measurement with the new preamplifier with that needed with a conventional preamplifier. Also, the dose rates for above conditions were measured by a commercial dose rate meter. Results show that the new preamplifier reduced the number of X-ray photons needed by two orders of magnitude compared with the conventional one.

RPC performance with HARDROC based readout

The proposed 51 kton magnetized Iron Calorimeter (ICAL) detector at India based Neutrino Observatory (INO) aims to investigate atmospheric neutrino oscillations. ICAL will use approximately 29000 glass-based Resistive Plate Chambers (RPCs) as active detector elements, that require millions of electronic channels to be read. Therefore, a multi-channel readout Application Specific Integrated Circuit (ASIC) named as HARDROC can be considered as a possible option. The ASIC is a 64 channel analog-digital front-end chip that can read negative fast and short input signals. Each of the HARDROC channels features a current sensitive pre-amplifier coupled to the triple-branch shaper stage and then 3 low offset discriminators. A comparative performance study of the RPC detector with HARDROC ASIC and with custom electronics, based on CAEN modules and HMC pre-amplifiers, was conducted. Measurements were made on a 30cm × 30cm glass RPC detector using the cosmic rays. The purpose of this work was to compare detector performance in terms of their strip detective efficiency and count rate.

Design of charge-sensitive and current-sensitive preamplifiers for electrostatic sensor

In this paper, the signal shape similarity degree is defined as quantitative criteria to distinguish charge-sensitive or current-sensitive preamplifier of electrostatic sensor. To establish the relationship between the similarity degree and the preamplifier, the rate (k) of the cutoff frequency of the preamplifier to the highest frequency of the induced current signal is presented. It is found that there are monotonic relationships between the similarity degree and k, which are built and used to design charge-sensitive and current-sensitive preamplifiers with different requirements. The results of the single particle free-fall experiment verify the effectiveness of this method.

Preliminary Design of Integrated Digitizer Base for Photomultiplier Tube

In many physical experiments and applications with photomultiplier tubes (PMTs), high-speed pulse digitalization is used extensively. The current pulse from a PMT has a rising time of several to a hundred nanoseconds. The current pulse shape can be used to obtain the pulse energy and discriminate between different particles. The conventional readout system with a PMT uses the discrete or integrated pulse-shaping circuits and analogue-to-digital converter boards which are based on the NIM or VME system to implement the data acquisition function. In many applications, such as security instruments, there are only several PMTs used in the whole system, or in some distributed applications, long-distance analogue cable with high-voltage power cable is not applicable due to the tremendous number of channels and enormous distributed space. In this paper, an integrated digitizer base is designed and interfaced with a Cs2LiYCl6 (CLYC) scintillator with a PMT. The CLYC scintillator has the ability to realize the pulse shape discrimination (PSD) between the neutron and gamma-rays. There is only one Gigabit of unscreened twisted-pair cable needed for over 700 Mbps TCP data throughput and more than 10 W power. The boards of high voltage supply, current sensitive preamplifier, 500 MSPS/12-Bit ADC (Analog-to-Digital Converter), readout module based on ZYNQ SoC (System on Chip), power over Ethernet, and user interface circuits are stacked with board-to-board connectors. The system can achieve 4.6% gamma-ray energy resolution at 662 keV with a 20-{\mu}s pulse integral and PSD figure-of-merit of ~3.0 for the whole energy of neutrons and gamma-rays. This integrated digitizer base can also be interfaced with other detectors with a PMT.

Magnetic Search Coil (MSC) of Plasma Wave Experiment (PWE) aboard the Arase (ERG) satellite

This paper presents detailed performance values of the Magnetic Search Coil (MSC) that is part of the Plasma Wave Experiment on board the Arase (ERG) satellite. The MSC consists of a three-axis search coil magnetometer with a 200-mm-long magnetic core. The MSC plays a central role in the magnetic field observations, particularly for whistler mode chorus and hiss waves in a few kHz frequency range, which may cause local acceleration and/or rapid loss of radiation belt electrons. Accordingly, the MSC was carefully designed and developed to operate well in harsh radiation environments. To ascertain the wave-normal vectors, polarizations, and refractive indices of the plasma waves in a wide frequency band, the output signals detected by the MSC are fed into the two different wave receivers: one is the WaveForm Capture/Onboard Frequency Analyzer for waveform and spectrum observations in the frequency range from a few Hz up to 20 kHz, and the other is the High Frequency Analyzer for spectrum observations in the frequency range from 10 to 100 kHz. The noise equivalent magnetic induction of the MSC is 20,{hbox {fT/Hz}}^{1/2} at a frequency of 2 kHz, and the null depth of directionality is − 40 dB, which is equivalent to an angular error less than 1^{circ }. The MSC on board the Arase satellite is the first experiment using a current-sensitive preamplifier for probing the plasma waves in the radiation belts.

Particle identification using digital pulse shape discrimination in a nTD silicon detector with a 1 GHz sampling digitizer

In beam test experiments have been carried out for particle identification using digital pulse shape analysis in a 500 μm thick Neutron Transmutation Doped (nTD) silicon detector with an indigenously developed FPGA based 12 bit resolution, 1 GHz sampling digitizer. The nTD Si detector was used in a low-field injection setup to detect light heavy-ions produced in reactions of ∼ 5 MeV/A 7Li and 12C beams on different targets. Pulse height, rise time and current maximum have been obtained from the digitized charge output of a high bandwidth charge and current sensitive pre-amplifier. Good isotopic separation have been achieved using only the digitized charge output in case of light heavy-ions. The setup can be used for charged particle spectroscopy in nuclear reactions involving light heavy-ions around the Coulomb barrier energies.

Current-Sensitive CMOS Preamplifier for Investigating Space Plasma Waves by Magnetic Search Coils

In order to considerably reduce circuit resources (mass, volume, and power) for the analog front ends of plasma wave measurement systems, a current-sensitive preamplifier for magnetic search coils (MSCs) is designed with standard 0.25- μm complementary metal-oxide-semiconductor (CMOS) technology. Since the input noise current determines the output noise levels around the resonant frequency of an MSC, a CMOS preamplifier operating with low noise current is suitable when combined with an MSC instead of using bipolar junction transistors. The current-sensitive CMOS preamplifier consists of a current amplifier for the detection of current flowing through the MSC and an equalizer for adjusting the transfer function. A prototype of the circuit structure was fabricated on a 1.9 × 3.3- mm2-silicon chip. The noise equivalent magnetic induction of the CMOS preamplifier combined with a 100-mm-long MSC is 3.5 pT/Hz1/2 at 10 Hz and 30 fT/Hz1/2 at 2 kHz with a power consumption of 4.6 mW for a 3.3-V supply. This paper is the first to examine a current-sensitive CMOS preamplifier for probing plasma waves.

Front-end electronics of the Belle II drift chamber

This paper describes the performance of the Belle II central drift chamber (CDC) front-end electronics. The front-end electronics consists of a current sensitive preamplifier, a 1/t cancellation circuit, baseline restorers, a comparator for timing measurement and an analog buffer for the dE/dx measurement on a CDC readout card. The CDC readout card is located on the endplate of the CDC. Mass production will be completed after the performance of the chip is verified. The electrical performance and results of a neutron/gamma-ray irradiation test are reported here.

A Front-End electronics board for single photo-electron timing and charge from MaPMT

A Front-End (FE) design based on commercial operational amplifiers has been developed to read-out signals from a Multianode PhotoMultiplier Tube (MaPMT). The overall design has been optimised for single photo-electron signal from the Hamamatsu H8500. The signal is collected by a current sensitive preamplifier and then it is fed into both a ECL fast discriminator and a shaper for analog output readout in differential mode. The analog signal and the digital gates are then registered on VME ADC and TDC modules respectively. Performances in terms of linearity, gain and timing resolution will be discussed, presenting results obtained on a test bench with differentiated step voltage inputs and also with a prototype electronic board plugged into the H8500 PMT illuminated by a picosecond laser.

PESIC: An Integrated Front-End for PET Applications

An ASIC front-end has been developed for multianode photomultiplier based nuclear imaging devices. Its architecture has been designed to improve resolution and decrease pile-up probability in positron emission tomography systems which employ continuous scintillator crystals. Analog computation elements are isolated from the photomultiplier by means of a current sensitive preamplifier stage. This allows digitally programmable adjustment of every anode gain, also providing better resolution in gamma event position calculation and a shorter front-end deadtime. The preamplifier stage also offers the possibility of using other types of photomultiplier devices such as SiPM. The ASIC architecture includes measurement of the depth of interaction of the gamma event based on the width of the light distribution in order to reduce parallax error and increase spatial resolution during image reconstruction stage. An output stage of transresistance amplifiers offer voltage output signals which may be introduced in the A/D conversion stage with no further processing.

Front-end circuit for position sensitive silicon and vacuum tube photomultipliers with gain control and depth of interaction measurement

Silicon Photomultipliers, though still under development for mass production, may be an alternative to traditional Vacuum Photomultipliers Tubes (VPMT). As a consequence, electronic front-ends initially designed for VPMT will need to be modified. In this simulation, an improved architecture is presented which is able to obtain impact position and depth of interaction of a gamma ray within a continuous scintillation crystal, using either kind of PM. A current sensitive preamplifier stage with individual gain adjustment interfaces the multi-anode PM outputs with a current division resistor network. The preamplifier stage allows to improve front-end processing delay and temporal resolution behavior as well as to increase impact position calculation resolution. Depth of interaction (DOI) is calculated from the width of the scintillation light distribution, which is related to the sum of voltages in resistor network input nodes. This operation is done by means of a high-speed current mode scheme.

PISA – an experiment for fragment spectroscopy at the Internal Beam of COSY: application of an Axial Ionization Chamber

The Proton-Induced SpAllation (PISA) experiment performed at the internal beam facility of the COSY storage ring in Jülich, Germany, which is aimed at the precise measurement of double differential cross-sections over a broad range of energies and angles for spallation reactions induced by protons of 200– 2500 MeV energy in various targets, is presented. In this paper the emphasis is put on the design, principles of operation and performance of a Bragg Curve Detector (BCD) optimized for internal beam experiments at storage rings. Very clean and distinct product identification (with Z up to ∼14) from reactions, in which a Ni target was bombarded with a 1.9 GeV circulating proton beam, is obtained. The individual elements are resolved for emission energies higher than 0.5 MeV/ nucleon . Moreover, due to the detector read-out achieved by coupling a specially designed current sensitive preamplifier directly to a sampling ADC, the shape analysis of the signals from the BCD allows the isotope identification of light particles with A up to ∼11. It is also found that the BCD can be used efficiently as a thin Δ E detector for the telescope consisting of the BCD and a series of silicon detectors.

A simple low-dissipation amplifier for cryogenic STM

A current sensitive preamplifier designed for low-temperature scanning tunneling microscopy applications is presented. It combines the dc current measurement necessary for the feedback loop operation with a low noise ac measurement used for spectroscopy. The active device is a high electron mobility transistor which was chosen for its low input capacitance and excellent low-temperature performance. The power dissipation of the transistor can be kept at about 10 μW making it compatible with a variety of cryogenic systems. The ac current sensitivity is about 4 fA/√Hz at 4.2 K.

Fast wire per wire X-ray data acquisition system for time-resolved small angle scattering experiments

Most of the X-ray multi-wire gas detectors used at the EMBL Hamburg outstation for time-resolved studies of biological samples are readout, using the delay line method. The main disadvantage of such readout systems is their event rate limitation introduced by the delay line and the required time to digital conversion step. They also lack the possibility to deal with multiple events. To overcome these limitations, a new approach for the complete readout system was introduced. The new linear detection system is based on the wire per wire approach where each individual wire is associated to a preamplifier/discriminator/counter electronics channel. High-density, front-end electronics was designed around a fast current sensitive preamplifier. An eight-channel board was designed to include the preamplifiers-discriminators and the differential ECL drivers output stages. The detector front-end consists of 25 boards directly mounted inside the detector assembly. To achieve a time framing resolution as short as 10 /spl mu/s, very fast histogramming is required. The only way to implement this for a high number of channels (200 in our case) is by using a distributed system. The digital part of the system consists of a crate controller, up to 16 acquisition boards (capable of handling fast histogramming for up to 32-channels each) and an optical-link board (based on the Cypress 'Hot-Link' chip set). Both the crate controller and the acquisition boards are based on a standard RISC microcontroller (IDT R3081) plug-in board. At present, a dedicated CAMAC module which we developed is used to interface the digital front-end acquisition crate to the host via the optical link.

On the noise behaviour of DMILL charge and current-sensitive preamplifier architectures

Novel configurations of current and voltage-sensitive preamplifiers in DMILL technology intended for calorimetry applications are discussed. A broad set of noise characterisation tests, including room temperature, cryogenic operation and radiation effects, is given. It is shown that in cryogenic conditions the noise behaviour is considerably less current dependent than at room temperature.

Monolithic GaAs current-sensitive cryogenic preamplifier for calorimetry applications

We have realized low-noise monolithic GaAs preamplifiers using ion- implanted technology , to operate under low temperature and high radiation field conditions. The evaluation of noise, amplitude and timing distributions of a batch taken after first mass-production run is presented. The current-sensitive preamplifier is linear up to 8 mA of input current and able to cope a 2.2 nF detector capacitance, showing fast response ( GBW product ∼ 1.7GHz) and very low series noise. Very good noise performance at LAr temperature is obtained by using large area MESFET ( l · w = 3. 24000μm 2 ) as a head transistor, which exhibits at 8mA standing current and only 10mW power dissipation, intrinsic gain μ = g m · r ds = 15 and noise referred to the input 0.30 ÷ 0.35 H z n ¯ V According to our estimation, second stage noise contribution is negligible. Radiation damage from neutrons and γ-irradiations as well as protection network against HV discharges are discussed.

Single photon imaging X-ray spectrometers using low noise current preamplifiers with dc voltage bias

We have developed superconducting single-photon imaging X-ray detectors with an energy resolution of 54 eV at 6 keV and a spatial resolution of 1 /spl mu/m over an effective length of 40 /spl mu/m. They utilize a current-sensitive low-noise preamplifier with a dc voltage bias. It has a signal bandwidth of 300 kHz, current noise of i/sub n/=0.26 pA//spl radic/(Hz) and voltage noise of e/sub n/=0.5 nV//spl radic/(Hz) with an input capacitance of 200 pF under operating conditions. Injected pulses with a charge Q=3.7/spl middot/10/sup 6/ electrons have been measured with a standard deviation /spl sigma/Q=3400 electrons, corresponding to an electronic noise of 13 eV at 6 keV.

A transimpedance CMOS multichannel amplifier with a 50 Ω-wide output range buffer for high counting rate applications

A fast transimpedance multichannel amplifier has been designed, fabricated in CMOS 1.2-/spl mu/m technology and tested. Each channel consists of a current sensitive preamplifier followed by a voltage amplification stage and an on-chip buffer able to drive 50 /spl Omega/ loads with an output range of /spl plusmn/800 mV. Measured peaking time at the output is 40 ns and the circuit recovers to baseline in 90 ns. This results in a counting capability of more than 10/sup 7/ hits/s, Signals of both polarities can be handled. The first two stages consume a total of 2 mW per channel and the 50 /spl Omega/ buffer consumes another 17 mW. The equivalent noise charge (ENC) is 1100 e/sup -/ rms with a slope of 40e/sup -//pF. The IC is intended for use in gas and solid-state detectors with high particle rate and extensive charge release as in high energy calorimetry.